mineral
Chalcedony Pebble
Cryptocrystalline Quartz (SiO2)
Hardness: 6.5-7 Mohs. Color: Translucent tan, yellow, or grey. Luster: Waxy to vitreous. Crystal structure: Hexagonal (monoclinic/trigonal at microscopic level). Cleavage: None, exhibits conchoidal fracture.
- Hardness
- 6
- Color
- Translucent tan, yellow, or grey
- Luster
- Waxy to vitreous
Identified More mineral →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 Mohs. Color: Translucent tan, yellow, or grey. Luster: Waxy to vitreous. Crystal structure: Hexagonal (monoclinic/trigonal at microscopic level). Cleavage: None, exhibits conchoidal fracture.
Formation & geological history
Formed via the deposition of silica from groundwater in cavities of volcanic or sedimentary rocks. This specimen is water-worn, likely from a fluvial or coastal environment.
Uses & applications
Used for lapidary work, jewelry (beads and cabochons), and as an abrasive in some industrial processes.
Geological facts
Chalcedony is an umbrella term for many variety names like agate, jasper, and carnelian. This specific weathered pebble is a common find in riverbeds and beaches worldwide.
Field identification & locations
Identify by its translucency when held to light, waxy feel, and its ability to scratch glass. Commonly found in gravel deposits, beaches, and desert washes.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
![Green Apatite on Albite (Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]) — mineral](https://media.rockidentification.com/2391a63f-fb20-47d5-af9a-2035851eb32e-thumbnail.jpg)
Green Apatite on Albite
Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]
mineral